Search results for " Suspension"
showing 10 items of 107 documents
CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of solid particle distribution
2013
Abstract Industrial tanks devoted to the mixing of solid particles into liquids are often operated at an impeller speed N less than Njs (defined as the lowest speed allowing the suspension of all particles): under such conditions the distribution of solid-particles is very far from being homogeneous and very significant concentration gradients exist. The present work is devoted to assessing the capability of Computational Fluid Dynamics (CFD) in predicting the particle distribution throughout the tank. The CFD model proposed by Tamburini et al. [58] and successfully applied to the prediction of the sediment amount and shape was adopted here to simulate the particle distribution under partia…
Computer active control of damping fluid of a racing superbike suspension scheme for road safety improvement spin-off
2008
This paper describes in detail a computational investigation of a newly-conceived scheme of hydraulic active racing motorcycle suspension and its design application based on a computer-aided control of damping fluid. Through ad hoc tests on a full-scale model setup and the theoretical approach of a non linear 8th-order suspension scheme, this study gives enhancement of the damping fluid active control on the feedback branch of the entire control system for significant improvement of the suspension response to typical road inputs. Briefly, the fluid flow in suspension dampers - generated through well-suited high-pressure hydraulic circuit - shall be conveniently controlled in direction and m…
Control of hysteretic instability in rotating machinery by elastic suspension systems subject to dry and viscous friction
2010
Abstract Most of the undesired whirling motions of rotating machines can be efficiently reduced by supporting journal boxes elastically and controlling their movement by viscous dampers or by dry friction surfaces normal to the shaft axis, which rub against the frame. In the case of dry dampers, resonance ranges of the floating support configuration can be easily cut off by planning a motionless adhesive state of the friction surfaces. On the contrary, the dry friction contact must change automatically into sliding conditions when the fixed support resonances are to be feared. Moreover, the whirl amplitude can be restrained throughout the speed range by a proper choice of the suspension-to-…
Molte Palermo. Temi
2019
Nel tema delle incompiute idee di città possibili si riconoscerà il paradigma connotativo dello stesso divenire di Palermo, lungo un percorso millenario di processi di trasformazione nessuno dei quali portato a compimento, in virtù di quel valore distintivo di exemplum che non necessita di ulteriori e conclusive dimostrazioni. Il corso della storia, del resto, ha imposto a Palermo il ciclico riproporsi di destini interrotti. Tale si rilevò l’invenzione della città capitale, quella della “quadratura geometrica e della croce di strade” sovrimpressa a quella archetipica e fondativa della Pan-ormos scambiatrice. E l’incompiutezza sarà il tratto distintivo della città dei rettifili stradali otto…
Role of Ovarian Suspension in Preventing Postsurgical Ovarian Adhesions in Patients with Stage III-IV Pelvic Endometriosis: A Systematic Review.
2018
Endometriosis is a benign complex gynecological condition with high morbidity that affects women of reproductive age. Pelvic adhesion formation represents a serious clinical challenge in the management of patients with endometriosis. Several interventions have been proposed over the last few years aiming to reduce post-operative ovarian adhesions formation. The aim of this study is to summarize the evidence of the efficacy of ovarian suspension in the prevention of post-operative ovarian adhesions formation in women undergoing laparoscopic surgery for stage III-IV endometriosis. The research was conducted using electronic databases. A review of the abstracts of all references retrieved from…
Output-feedback-based H∞ control for vehicle suspension systems with control delay
2014
This paper deals with the problem of output-feedback H∞ control for a class of active quarter-car suspension systems with control delay. The dynamic system of the suspension systems is first formed in terms of the control objectives, i.e., ride comfort, road holding, suspension deflection, and maximum actuator control force. Then, the objective is to the design of the dynamic output-feedback H∞ controller in order to ensure asymptotic stability of the closed-loop system with H∞ disturbance attenuation level and the output constraints. Furthermore, using Lyapunov theory and linear matrix inequality (LMI) approach, the existence of admissible controllers is formulated in terms of LMIs. With t…
Inhibition of Xanthine Oxidase by Allopurinol Prevents Skeletal Muscle Atrophy: Role of p38 MAPKinase and E3 Ubiquitin Ligases
2012
International audience; Abstract Top Alterations in muscle play an important role in common diseases and conditions. Reactive oxygen species (ROS) are generated during hindlimb unloading due, at least in part, to the activation of xanthine oxidase (XO). The major aim of this study was to determine the mechanism by which XO activation causes unloading-induced muscle atrophy in ratsand its possible prevention by allopurinol, a well-known inhibitor of this enzyme. For this purpose we studied one of the main redox sensitive signalling cascades involved in skeletal muscle atrophy i.e. p38 MAPKinaseand the expression of two well known muscle specific E3 ubiquitin ligases involved in proteolysis, …
Sex differences in behavioral traits related with high sensitivity to the reinforcing effects of cocaine
2021
Cocaine is the most prevalent illegal stimulant drug in Europe among the adult population. Its abuse is characterized by a faster substance abuse disorder (SUD) development than other drugs, with high vulnerability to relapse. However, there does not exist an effective treatment for cocaine dependence. Sex differences have been reported in psychological disorders including SUD. For this reason, it is essential to identify risk factors that predict susceptibility or resilience to cocaine addiction for the development of effective prevention strategies considering sex differences. In the present study, the main objective was to determine more sensitive phenotypes to the conditioned reinforcin…
Peripheral and central CB1 cannabinoid receptors control stress-induced impairment of memory consolidation
2016
Stressful events can generate emotional memories linked to the traumatic incident, but they also can impair the formation of nonemotional memories. Although the impact of stress on emotional memories is well studied, much less is known about the influence of the emotional state on the formation of nonemotional memories. We used the novel object-recognition task as a model of nonemotional memory in mice to investigate the underlying mechanism of the deleterious effect of stress on memory consolidation. Systemic, hippocampal, and peripheral blockade of cannabinoid type-1 (CB1) receptors abolished the stress-induced memory impairment. Genetic deletion and rescue of CB1 receptors in specific ce…
Depressive-like symptoms in a reserpine-induced model of fibromyalgia in rats.
2015
Since the pathogenesis of fibromyalgia is unknown, treatment options are limited, ineffective and in fact based on symptom relief. A recently proposed rat model of fibromyalgia is based on central depletion of monamines caused by reserpine administration. This model showed widespread musculoskeletal pain and depressive-like symptoms, but the methodology used to measure such symptoms has been criticized. Evidence relates the high prevalence of pain and depression in fibromyalgia to common pathogenic pathways, most probably focused on the monoaminergic system. The present study aims at a validation of the reserpine model of fibromyalgia. For this purpose, rats undergoing this model have been …